Known high temperature adhesives have gained great popularity in the aerospace and microelectronics industries. These adhesives are used for a variety of purposes ranging from bonding substrates in aerospace industry to attaching semiconductor dies or chips to a substrate in electronics industry. One common problem associated with the known adhesives is that upon exposure to high temperatures, they exhibit a tendency to evolve gases formed during curing or post-curing of the adhesive. Evolution of gases results in void formation in the adhesive thereby adversely affecting thermal and electrical properties thereof. Other common problems of the known high temperature adhesives relate to poor processability and low glass transition temperatures. The known adhesives have poor processability in that curing thereof is accompanied by volatile formation and glass transition temperatures are too low for high temperature processing. For instance, although epoxy resins are thermosetting, they have rather low glass transition temperatures with Epon.RTM. 825 polymer having glass transition temperature of about 140.degree. C.
As was already mentioned, the known typical high temperature adhesives are difficult to process. Examples of such known high temperature adhesives include epoxies, polyimides, and polybenzimidazoles. The known high temperature adhesives have superior mechanical properties and are lighter and more economical to produce than metals. Epoxies cannot be used as adhesives for prolonged temperature exposure in excess of about 140.degree. C. due to thermal and mechanical instabilities. Polyimides and polybenzimidazoles are difficult to process and volatiles are evolved during the curing or polymerization reaction.